Apparatus for processing wafer

ABSTRACT

An apparatus for processing wafer is provided, in which a re-adhesion of the slurry to the wafer edge, which has been adhered to the elastic abrasion member, can be inhibited, since a stronger contact of the rotating elastic abrasion member with the wafer edge, which is occurred when the rotating elastic abrasion member enters to the surface of the wafer, is avoided, and further, an abrasion of the elastic abrasion member can be inhibited. The apparatus for processing wafer is an apparatus for processing wafers, wherein a shaft center of the mechanism for rotating the wafer is inclined relative to a shaft center of the abrading-rotating mechanism, so that a distance between the support member and the wafer in a position where the elastic abrasion member enters the inner side of the surface of the wafer from the outer side thereof due to the actuation toward the predetermined direction by the abrading-rotating mechanism is larger than the distance between the support member and the wafer in a position where the elastic abrasion member escapes from the inner side of the surface of the wafer to the outer side thereof.

This application is based on Japanese patent application No. 2007-44,539, the content of which is incorporated hereinto by reference.

BACKGROUND

1. Technical Field

The present invention relates to an apparatus for processing wafers that is capable of fretting at least one side of a disc-shaped wafer.

2. Related Art

Conventionally, a typical apparatus for processing wafers includes, for example, an apparatus described in Japanese Patent Laid-Open No. 2002-177,898. The apparatus for processing wafers described in Japanese Patent Laid-Open No. 2002-177,898 is shown in FIG. 4. In this apparatus for processing wafers, a wafer 10 is held with a roller chuck, sponge-like brushes 12 are installed to a disc-shaped brush base 11. Further, the surface of the wafer 10 is in parallel with the lower surface of the brush base 11. In order to conduct a scrub-cleaning over the edge of the wafer 10, an offset positional relationship between a shaft center of the wafer 10 and a shaft center of the brush base 11 is employed. Further, portions of the brush 12 installed to the brush base 11 are protruded beyond the surface of the wafer 10. When the wafer 10 is scrub-cleaned, both of the wafer 10 and the brush base 11 rotate, and the sponge-like brushes 12 are pressed to the front and the back surface of the wafer 10. Then, a liquid or slurry (L) for rinsing is discharged from the center of the brush base 11 to clean the wafer 10.

However, the apparatus for processing wafers disclosed in Japanese Patent Laid-Open No. 2002-177,898 bears improvements in terms of re-adhesion of particles in the slurry.

For example, since the lower surface of the brush 12 (brush base 11) is arranged to be in parallel with the surface of the wafer 10 in the apparatus for processing wafers disclosed in Japanese Patent Laid-Open No. 2002-177,898, the apparatus is configured that the entire lower surface of the brush 12 is uniformly pressed against the surface of the wafer 10 as shown in FIG. 5B. As shown in FIGS. 5A and 5B, the shaft center 20 of the wafer the central axis 21 of the brush base are not relatively inclined. When the scrub-cleaning is conducted, the brush 12 is pushed onto the surface of the wafer 10 at a fixed pressure for providing better scrub-cleaning. Therefore, a leading edge of the brush 12 on the surface of the wafer 10 is squashed as shown in FIG. 6, providing a lower height of the brush 12 (the brush on the back side of the wafer is not illustrated).

On the other hand, the leading edge of the brush 12 protruding beyond the wafer 10 is not squashed. Since the brush base 11 is rotated, actions of the portions of the brush 12 for traveling from the “surface of the wafer 10” to the “protruded section” (without wafer 10) and traveling from the “protruded section” (without wafer 10) to the “surface of the wafer 10” are repeated, while the portion of brush 12 are revolved. When the action for traveling from the “protruded section” (without wafer 10) to the “surface of the wafer 10” is achieved, the protruded portion of the brush 12 is in strong contact with the edge of the wafer 10, and gradually runs on the surface of the wafer 10 while being squashed. A section Z represented by a thick curved line in FIG. 7 indicates a section where the brush 12 is in strong contact with the wafer 10, when the protruded portion of the brush 12 is entered onto the surface of the wafer 10 due to the rotation of the brush 12. Therefore, particles originally contained in the slurry and adhered in the brush 12 may possibly adhered again onto the edge of the wafer 10 in the section Z.

Such re-adhesion is more considerably occurred as the pushing pressure of the brush 12 onto the wafer 10 is larger. Further, the strong contact between the protruded portion of the brush 12 and the edge of the wafer 10 may accelerate an abrasion of the leading edge of the brush 12 located in the outside of the wafer 10.

Further, a reduced pushing pressure of the brush 12 onto the wafer 10 leads to an insufficient removal-ability of the slurry, causing problems such as debasements in the qualities of the products.

SUMMARY

According to one aspect of the present invention, there is provided an apparatus for processing wafers, which is adopted to abrade at least one side of a disc-shaped wafer, comprising: a wafer-rotating mechanism, capable of actuating a rotation of the wafer; an abrasion unit configured to have an elastic abrasion member supported by a support member, the elastic abrasion member being capable of abrading a surface of the wafer; and an abrading-rotating mechanism for actuating the abrasion unit to be rotated for a predetermined direction to cause a revolution of the elastic abrasion member, in a position where at least a portion of the elastic abrasion member travels between an inner portion in the surface of the wafer and an outer portion thereof, wherein a shaft center of the wafer-rotating mechanism is inclined relative to a shaft center of the abrading-rotating mechanism, so that a distance between the support member and the wafer in a position where the elastic abrasion member enters the inner side of the surface of the wafer from the outer side thereof due to the actuation toward the predetermined direction by the abrading-rotating mechanism is larger than the distance between the support member and the wafer in a position where the elastic abrasion member escapes from the inner side of the surface of the wafer to the outer side thereof.

In such apparatus for processing wafer, the distance between the support member and the wafer in a position where the elastic abrasion member enters the inner side of the surface of the wafer from the outer side thereof is selected to be larger than the distance therebetween in a position where the elastic abrasion member escapes from the inner side of the surface of the wafer to the outer side thereof, so that a stronger contact of the rotating elastic abrasion member with the wafer edge, which is occurred when the rotating elastic abrasion member enters to the surface of the wafer, is avoided.

According to the present invention, an apparatus for processing wafer is provided, in which a re-adhesion of the slurry to the wafer edge, which has been adhered to the elastic abrasion member, can be inhibited, since a stronger contact of the rotating elastic abrasion member with the wafer edge, which is occurred when the rotating elastic abrasion member enters to the surface of the wafer, is avoided, and further, an abrasion of the elastic abrasion member can be inhibited.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, advantages and features of the present invention will be more apparent from the following description of certain preferred embodiments taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a schematic cross-sectional view, showing an apparatus for processing wafers;

FIG. 2 is a schematic plan view, showing an apparatus for processing wafers;

FIG. 3 is a schematic cross-sectional view, showing an apparatus for processing wafers;

FIG. 4 is a schematic perspective view, showing a conventional apparatus for processing wafers;

FIG. 5A is a schematic plan view, showing a conventional apparatus for processing wafers;

FIG. 5B is a schematic cross-sectional view showing the conventional apparatus for processing wafers;

FIG. 6 is a schematic cross-sectional view, showing a conventional apparatus for processing wafers; and

FIG. 7 is a schematic plan view, showing a conventional apparatus for processing wafers.

DETAILED DESCRIPTION

The invention will be now described herein with reference to illustrative embodiments. Those skilled in the art will recognize that many alternative embodiments can be accomplished using the teachings of the present invention and that the invention is not limited to the embodiments illustrated for explanatory purposed.

An exemplary implementation of the present invention will be described as follows in reference to FIGS. 1 and 2. In the following description, an identical designation will be employed for identifying an element, which also appears in the above-described descriptions for the conventional technology, and the duplicated description will not be presented.

FIG. 2 is a schematic plan view of an apparatus for processing wafers. The apparatus for processing wafer in the present embodiment is an apparatus for processing wafers, which is adopted to abrade at least one side of a disc-shaped wafer 30, comprising: a wafer-rotating mechanism 50, capable of actuating a rotation of the wafer 30; an abrasion unit 33 configured to have an elastic abrasion member 32 supported by a support member 31, the elastic abrasion member 32 being capable of abrading a surface of the wafer 30; and an abrading-rotating mechanism 51 for actuating the abrasion unit 33 to be rotated toward a predetermined direction to revolve the elastic abrasion member 32, in a position where at least a portion of the elastic abrasion member 32 travels between an inner portion in the surface of the wafer 30 and an outer portion thereof, wherein a shaft center of wafer-rotating mechanism 50 for rotating the wafer 30 is inclined relative to a shaft center of the abrading-rotating mechanism 51, so that a distance between the support member 31 and the wafer 30 in a position where the elastic abrasion member 32 enters the inner side of the surface of the wafer 30 from the outer side thereof due to the actuation toward the predetermined direction by the abrading-rotating mechanism 51 is larger than the distance between the support member 31 and the wafer 30 in a position where the elastic abrasion member 32 escapes from the inner side of the surface of the wafer 30 to the outer side thereof.

Further, a section Z represented by a thick curved line in FIG. 2 indicates a section where a portion of the elastic abrasion member 32 enters in the inner side in the surface of the wafer 30 from the outside thereof due to a revolution of the elastic abrasion member 32. In particular, the section indicates a section where the elastic abrasion member 32 is in strong contact with the edge of the wafer 30.

The apparatus for processing wafers includes the wafer-rotating mechanism 50, the abrasion unit 33 and the abrading-rotating mechanism 51.

The wafer-rotating mechanism 50 is adopted to actuate the wafer 30 to be rotated around a shaft center 40 thereof.

The abrasion unit 33 has a structure, in which the elastic abrasion member 32 for abrading the surface of the wafer 30 is supported by the support member 31. The abrasion unit 33 rotates around the shaft center 41 of the abrading-rotating mechanism 51 to provide a revolution of the elastic abrasion member 32. At least a portion of the revolving elastic abrasion member 32 abrades the surface of the wafer 30 while traveling between the inner side and the outer side of the surface of the wafer 30. Such travelling of the elastic abrasion member 32 achieves a cleaning of the entire surface of the wafer 30.

Further, a plurality of elastic abrasion members 32 are radially supported by the support member 31 in the abrasion unit 33. Even if a plurality of elastic abrasion members 32 are radially supported, the strong contact of the rotating elastic abrasion members 32 with the edge of the wafer 30 occurred when the elastic abrasion members 32 enter to the surface of the wafer 30 is avoided, so that a re-adhesion of the slurry, which may otherwise adhered to the edge of the elastic abrasion member 32, can also be inhibited.

The abrading-rotating mechanism 51 is adopted to actuate the abrasion unit 33 to be rotated in a fixed direction in a position where at least a portion of the revolving elastic abrasion member 32 moves between the inner side and the outer side in the surface of the wafer 30.

FIG. 1 is a diagram, representing a cross section along line A-A′ in FIG. 2. A shaft center 40 of the wafer-rotating mechanism 50 is inclined relative to a shaft center 41 of the abrading-rotating mechanism 51, so that a distance between the support member 31 and the wafer 30 in a position where the elastic abrasion member 32 enters the inner side of the surface of the wafer 30 from the outer side thereof due to the actuation toward the predetermined direction is larger than the distance between the support member 31 and the wafer 30 in a position where the elastic abrasion member 32 escapes from the inner side of the surface of the wafer 30 to the outer side thereof. An angle of the inclination between the shaft center 40 and the shaft center 41 may be preferably, for example, within a range of from 0.6 degree to 1.2 degree.

The inclined spatial relationship of the shaft center 41 of the abrading-rotating mechanism 51 achieves a condition that the pressing pressure of the elastic abrasion member 32 is minimized in the section for entering the surface of the wafer 30, and is maximized at the opposite angle side on the wafer 30. This allows preventing the elastic abrasion member 32 entering the surface of the wafer 30 from being in strong contact with the edge of the wafer 30. More specifically, a re-adhesion of the slurry, which has been originally adhered to the elastic abrasion member 32, to the edge of the wafer 30 can be inhibited, and further, an abrasion of the elastic abrasion member 32 can also be inhibited.

While the configuration having the shaft center 41 of the abrading-rotating mechanism 51, which is inclined relative to the shaft center 40, is shown in the present embodiment, an alternative configuration having the shaft center 40 of the wafer-rotating mechanism 50, which is inclined relative to the shaft center 41, may also be employed (FIG. 3).

In other words, the shaft center 40 of the wafer-rotating mechanism 50 and the shaft center 41 of the abrading-rotating mechanism 51 may be relatively tilted, so that the leading edge of the elastic abrasion member 32 is not pushed against the edge of the wafer 30 in the section Z.

While the configuration of the elastic abrasion members 32, which are radially supported, is employed in the present embodiment, an alternative configuration of the elastic abrasion members 32, which are uniformly supported on the support member 31, may also be employed. Members available for the elastic abrasion member 32 may include elastic members such as brush, sponge and the like. Further, tilting direction/angle, positions of the shaft centers, diameter/geometry/dimension of the abrasion unit or the like may be suitably optimized for solving the above-described problems.

Further, while the configuration having three wafer-rotating mechanisms 50 for rotating the wafer 30 is described in the present embodiment, number and positions of the wafer-rotating mechanisms 50 may not be particularly limited thereto.

Further, while the configuration having the abrasion unit 33 and the abrading-rotating mechanism 51, both of which are present on the front surface of the wafer 30, is described in the present embodiment, an alternative configuration having these unit/mechanism located on both the front and the back sides of the wafer 30 may also be employed to achieve similar advantageous effects.

Further, while the embodiment utilizing the wafer processing apparatus for cleaning is described in the present embodiment, other applications including polishing or the like, in addition to cleaning, may also be adapted.

The present embodiment and possible modifications thereof may be combined, unless the concepts thereof contradict. 

1. An apparatus for processing wafers, which is adopted to abrade at least one side of a disc-shaped wafer, comprising: a wafer-rotating mechanism, capable of actuating a rotation of said wafer; an abrasion unit configured to have an elastic abrasion member supported by a support member, said elastic abrasion member being capable of abrading a surface of said wafer; and an abrading-rotating mechanism for actuating said abrasion unit to be rotated for a predetermined direction to cause a revolution of said elastic abrasion member, in a position where at least a portion of said elastic abrasion member travels between an inner portion in the surface of said wafer and an outer portion thereof, wherein a shaft center of said wafer-rotating mechanism is inclined relative to a shaft center of said abrading-rotating mechanism, so that a distance between said support member and said wafer in a position where said elastic abrasion member enters the inner side of the surface of said wafer from the outer side thereof due to the actuation toward the predetermined direction by said abrading-rotating mechanism is larger than the distance between said support member and said wafer in a position where said elastic abrasion member escapes from the inner side of the surface of said wafer to the outer side thereof.
 2. The apparatus for processing wafers as set forth in claim 1, wherein a plurality of said elastic abrasion members are radially supported by said elastic abrasion member in said abrasion unit.
 3. The apparatus for processing wafers as set forth in claim 1, wherein the surface of said wafer is cleaned by abrading the surface with said elastic abrasion member of said abrasion unit.
 4. The apparatus for processing wafers as set forth in claim 2, wherein the surface of said wafer is cleaned by abrading the surface with said elastic abrasion member of said abrasion unit. 